Ethod of coating water-bottoms of vessels



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. -A .1V[oDOUGALL. METHOD OF COATING WATER BOTTOMS 0P VESSELS.

No. 553,590. Patented Jan. 28, 1896.

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. A. MoDOUGALL. METHOD OF COATING WATER BOTTOMS 0F VESSELS.

N0. 553,590. Patented Ja11.28, 1896.

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- No. 553,590. Patented Jan. .28, 1896.

ll i I 1 I M I UNITED STATES PATENT OFFICE.

ALEXANDER MCDOUGALL, OF DULUTH, MINNESOTA.

METHOD OF COATING WATER-B OTTOMS OF VESSELS.

SPECIFICATION forming part of Letters Patent No. 553,590, dated January28, 1896. Application filed May 22,1891. Serial No. 393,770. (Nospecimens.)

To all whom it may concern.-

Be it known that I, ALEXANDER McDon- GALL, a citizen of the UnitedStates, residing at Duluth, in the county of St. Louis and State ofMinnesota, have invented certain new and useful Improvements in Methodsof Coating ater-Bottoms of Vessels; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,which will enable others skilled in the art to which it appertains tomake and use the same.

It has been found that the double bottom of iron vessels becomesaffected and corroded by the salt bilge-water which accumulates therein.Under the regulations which are now prescribed to all American ironvessels it is required that the inside of the double bottom be coatedwith some impervious substance-such as coal-tar, creosote, or oil-sothat the salt bilge-water will not affect the iron. This imperviouscoating has been found to last only about three years, so that it has tobe renewed many times during the lifetime of a vessel. This has beendone heretofore with an ordinary paint-brush, with which the substanceis applied to the metal. Owing to the fact that the atmosphere withinthe double bottom of iron vessels is of such a character that a mancannot work therein for any extreme lengths of time, and for the reasonthat there are many extremely difficult angles and corners to bereached, it has been found that it is almost a matter of impossibilityto have the work done in a thorough manner by the old process.

My present invention relates to an improved method of coating the doublebottom ,of vessels with an impervious material for the purpose above setout; and the object of the invention is to provide a method whereby thismay be accomplished in a perfect manner and in much less time thanformerly without the necessity of aman going within the double bottom.

The present invention isespecially applicable for use in connection withthose metallic vessels which I have heretofore invented and which havebeen patented by me. Al-

though the present invention can be conveniently used with vessels ofthat particular type, I do not wish to confine myself to such use, sincethe invention maybe also applied to other varieties of iron vessels.

For a better comprehension of my invention, attention is directed to theaccompanying drawings, forming apart of this specification, and in whichFigure 1 is a sectional view of a Vessel of the type invented by me,showing the present invention in connection therewith; Fig. 2, alongitudinal sectional view of the same, and Fig. 3 a top elevation.

In all of the above views corresponding parts are designated by the sameletters of reference.

A represents the boat of the kind before referred to, being either atowboat proper or a steamboat. This boat is constructed of platesriveted to transverse ribs, so that the hull is practically a hollowshell. This hull is provided with a double bottom B. This double bottomanswers the ordinary purposes of the same, viz: to be filled with waterto partially submerge the hull when light and to prevent the bilge-waterfrom coming in contact with the cargo. \Vater is allowed to enter thiswater bottom from the outside through suitable valves, and this water isremoved therefrom by means of pipes a awithin the same and provided withbell-mouths extending near the bottom of the hull, and by which thewater maybe almost, entirely withdrawn. A pump 0, which is preferably asteam-pump, is mounted within an engineroom D at any suitable point, andis used to pump the water from the water-bottom.

In carrying out my improved method of coating the water-bottoms ofmetallic vessels I go about as follows, the description being applied toa boat of the form invented by me: The vessel is first moved within asuitable slip, which may be either cut into the land or else constructedof piling and timbers in the ordinary way. After entering the slip thevessel is secured therein in the ordinary manner by means of the usualhawsers. Instead of making use of a slip the vessel may be movedalongside of an ordinary wharf or dock, or, in some instances, the boatmay be secured adjacent to the shore, so that, as will be understood,the slip is not absolutely nccessary. Upon one or both sides of the slipor the wharf or the shore I place a tank E, but a barrel or reservoir orpit will answer the purpose just as well. The tank E is now partiallyfilled with water, either fresh or salt, and with this water is mixedthe substance with which it is desired to coat the water bot-tom. Thissubstance, which is either oil, coaltar, creosote, or analogouscomposition, will float on the surface of the water as soon as theagitation has ceased, caused by the introduction of the substance. It isnot necessary to wait until the water and the composition have becomethus separated in the tank, because the act of removing them therefromwill probably cause them to mix again. The water and composition are nowremoved from the tank on the dock-slip or shore and introduced withinthe water-bottom which is to be coated. This may be done by hand withbuckets, or in any other suitable way, but I prefer to effect thistransfer by means of the pump 0 and pipes a a, before described, sincethese elements form a part of the boat, and by means thereof the waterand composition can be introduced within the water-bottom in a verylittle time.

The water-bottom is to be filled entirely with the water andcomposition, which is then allowed to settle until the composition hasrisen to the surface of the water, and will come in contact with the topof the waterbottom, so as to effectively coat the same. As soon as thecomposition has risen to the surface of the water and has coated the topof the water-bottom the pump 0 is started and the water is pumped out ofthe water-bottom through the pipes to a and back into the tank E. Owingto the fact that the bell-mouths of the pipes Ct a are located very nearto the bottom of the vessel the water will be first removed from thewater-bottom, and as the composition sinks with the water it willeffectively coat the interior of the water-bottom, and in all its anglesand corners, and in a perfect manner.

The water and composition which is re turned to the tank may be usedover and over again until exhausted.

After all the water and composition has been removed from thewater-bottom I prefer to force air, preferably in a heated c011- dition,within the water-bottom, so as to dry the composition which adheres tothe sides and top thereof. This air may be admitted through the pipes aa, and will blow off through the usual manholes in the top of thewater-bottom. Instead of air, steam or any other drying agent may beused, and, if desired, the air may be of its normal temperature and notheated.

It will be evident that the final step in the method of forcing airwithin the water-bottom may be entirely done away with if it is notnecessary to dry the composition quickly.

It will also be understood that the waterbottom may be filled entirelywith compost tion, but it is preferable for economys sake to mix thecomposition with water.

The apparatus for carrying out the present invention may be changed andmodified in many respects, and it relates in no way to the presentinvention, which consists of the improved method set out in the claims.

Having now described my invention, what I claim as new therein, anddesire to secure by Letters Patent, is as follows:

1. The method of coating the water bottoms of vessels with an imperviouscomposition which consists in introducing amixture of the water and thecomposition within the water bottom so as to entirely fill the same;then in allowing the composition to rise tothe surface of the water soas to coat the under side of the top of the water bottom with thecomposition; then in removing the water first and the compositionafterward so as to coat the sides of the water bottom with thecomposition, and also to coat the bottom of the water bottom with thecomposition, substantially as set forth.

2. The method of coating the watenbottom of vessels with an imperviouscomposition,

which consists in introducing a mixture of water and the compositionwithin the waterbottom; then in allowing the composition to rise to thesurface of the water; then in removing the water first, and thecomposition afterward leaving a residue or coating of composition 5 andfinally in blowing air within the water-bottom so as to dry the coatingof the composition, substantially as set forth.

ALEXANDER l\ICDOUGALL.

In presence of FRANK L. DYER, LEONARD H. DYER.

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